Science Objectives for Everyone
Reaction Self Test is a portable, five-minute task that enables astronauts to monitor the daily effects of fatigue on performance while in space. Sleep restrictions and residual effects from sleep medications, slam shifts that change the sleep/wake cycle, and effects from spacewalks can cause fatigue and degrade astronaut performance. Periodically during the mission, and in association with major events, an astronaut performs a reaction-time test on a computer to measure changes in responses.

Science Results for EveryoneInformation Pending

The following content was provided by David F. Dinges, Ph.D., and is maintained in a database by the ISS Program Science Office.

Experiment Details

OpNom Reaction Self Test

Principal Investigator(s)

David F. Dinges, Ph.D., University of Pennsylvania, Philadelphia, PA, United States

Co-Investigator(s)/Collaborator(s)

Mathias Basner, Ph.D., M.D., MSc, University of Pennsylvania, Philadelphia, PA, United States

Daniel Mollicone, Ph.D., Philadelphia, PA, United States

Developer(s)Johnson Space Center, Human Research Program, Houston, TX, United States

The Psychomotor Vigilance Self Test on the International Space Station (Reaction Self Test) aids crewmembers to objectively identify when their performance capability is degraded by various fatigue-related conditions that can occur as a result of ISS operations and time in space (e.g., acute and chronic sleep restriction, slam shifts, extravehicular activity (EVA), and residual sedation from sleep medications).

Reaction Self Test evaluates the extent to which performance of ISS crewmembers is sensitive to fatigue from sleep loss and circadian (a rhythm of biological functions occurring in a 24-hour periodic cycle (e.g., sleeping, eating, etc.)) disruption during the mission, fatigue from work intensity during the mission, decline of performance with time during the mission, and carry-over effects of medications for sleep on board the ISS.

Reaction Self Test also evaluates the extent to which performance feedback (via a graphical interface) is perceived by ISS crewmembers as a useful tool for assessing performance capability.

Description

The Psychomotor Vigilance Self Test on the International Space Station (Reaction Self Test) provides crewmembers with objective feedback on neurobehavioral changes in vigilant attention, psychomotor speed, state stability, and impulsivity while on ISS missions. The Reaction Self Test is ideal for repeated use in space flight because unlike other cognitive tests, it is very brief while being free of learning effects and aptitude differences that make interpretation of other cognitive measures difficult. The Reaction Self Test was successfully deployed in three NASA Extreme Environment Mission Operation (NEEMO) missions (9, 12 and 13) and found to be acceptable by the 12 astronauts, whose data provided a normative database for development of a feedback interface for the Reaction Self Test to alert crewmembers to their performance level. These data support the readiness of the Reaction Self Test for deployment and study on board the ISS.

The following are the specific aims of the project:

To evaluate the extent to which Reaction Self Test performance of crewmembers is sensitive to fatigue from sleep loss and circadian disruption during ISS missions. This includes the following conditions evaluated individually and in aggregate:

extended wake duration between 16 hours

sleep restriction defined as total sleep time greater than 0 and less than 6 hours per 24-hour period

circadian perturbation associated with night work and slam shifting.

To evaluate the extent to which Reaction Self Test performance of crewmembers is sensitive to fatigue from work intensity during ISS missions. This includes the following conditions evaluated individually and in aggregate:

extend work durations up to 16 hours per day

more than 6 consecutive work days without a day off for rest

work requiring extravehicular activity (EVA).

To evaluate the extent to which Reaction Self Test performance of crewmembers declines with time in mission.

To evaluate the extent to which Reaction Self Test performance of crewmembers are sensitive to the carry-over effects of medications for sleep (e.g., zolpidem, ramelteon, etc.) on board the ISS.

To evaluate the extent to which Reaction Self Test performance feedback (via a graphical interface) is perceived by ISS crewmembers as a useful tool for assessing performance capability. This is addressed throughout the mission by crewmember ratings.

The Reaction Self Test addresses a number of high-priority NASA Behavioral Health and Performance research gaps including identifying the best ways to assess decrements in cognitive function and individual vulnerability to sleep loss, and to help ground and flight crews recognize and compensate for those changes.

Earth Applications

Reaction Self Test has been deployed in multiple NASA analog environments, underwater in the NASA Extreme Environment Mission Operation missions (NEEMO), The Haughton Mars Project (HMP) and Desert RATS as well as other federally sponsored research projects both in-lab and field trials including the Mars500 missions conducted in Russia. It has applications in understanding reaction times, lapses of attention, sleepiness, and impulsivity caused by fatigue and other factors found in demanding operational environments.

A minimum of 24 ISS crewmembers on approximately six month missions are needed as subjects for the experiment. Two subjects with one-year mission durations (launching on 42S) are also planned.

For six-month missions, crewmembers will have the following data collection schedule: Preflight sessions are performed at launch minus 180 (L-180), L-150, L-120, L-90, L-60, L-30, and L-7 through L-1. The postflight sessions are from R+0 to R+7 and R+30, R+60, and R+90. The inflight session is performed twice a day every fourth day of the mission starting on FD3. In addition to completing the test twice a day every fourth day, crewmembers are requested to complete the Reaction Self Test twice per day on each day of a sleep shift in addition to twice a day three days preceding a sleep shift, and Reaction Self Test twice per day for five days following the sleep shift. Crewmembers are also requested to perform the Reaction Self Test twice on the day preceding an EVA, and once immediately after the EVA and all its related activities have been completed.

For one-year missions, crewmembers will have the following data collection schedule: Preflight sessions are performed at launch minus 180 (L-180), L-150, L-120, L-90, L-60, and L-30 with one additional test between L-14 and L-1. The postflight sessions are a single session between R+0 and R+7 plus sessions at R+30, R+60, and R+90. The inflight session is performed twice a day every tenth day of the mission starting on FD3. The post-sleep test will consist of the questions only, while the pre-sleep test will consist of the questions and the PVT test. In addition to completing the test twice a day every tenth day, crewmembers are requested to complete the Reaction Self Test twice per day on each day of a sleep shift in addition to twice a day three days preceding a sleep shift, and Reaction Self Test twice per day for five days following the sleep shift. Crewmembers are also requested to perform the Reaction Self Test twice on the day preceding an EVA, and once immediately after the EVA and all its related activities have been completed.

Operational Protocols

During flight, it is imperative that the Reaction Self Test be completed regularly through the entire mission. The Reaction Self Test uses the HRF laptop or Station Support Computer (SSC) and takes about five minutes to complete. It includes pre-test questions, the reaction time test and feedback displays on the computer. The crewmember is requested to complete the Reaction Self Test twice a day every fourth day of the mission. In addition to completing the test twice a day every fourth day (every tenth day for one-year missions), crewmembers are requested to complete the Reaction Self Test twice per day on each day of a sleep shift in addition to twice a day three days preceding a sleep shift, and Reaction Self Test twice per day for five days following the sleep shift. Crewmembers are also requested to perform the Reaction Self Test twice on the day preceding an EVA, and once immediately after the EVA and all its related activities have been completed.

View of laptop computer in the Node 1 during the Reaction Self-Test (Psychomotor Vigilance Self-Test on the ISS) protocol by the Expedition 33 crew. The Node 1 table and a bulkhead covered in mission patches are also visible in the frame. NASA Image. + View Larger Image